546 Brazilian Corals and Coral Reefs. [September, 
above the water its growth is nearly finished, so we can trace its 
entire history from the beginning to the close. 
The long island of Itaparica, often called the garden of Bahia, 
fills up almost the entire south-western quarter of the large Bay 
of Bahia, and contracts its entrance to a width of about five miles. 
Its outer coast, running obliquely, facés for the most part the open 
sea, and is at the mercy of its boisterous waves. Skirting the 
central portion of this coast for a distance of nearly nine miles, 
is a slightly elevated coral reef, long siice abandoned by true 
living corals and given over to another class of workers, who are 
putting on the finishing touches and coating it with a hard and 
durable substance. 
This reef begins directly opposite the city of Bahia, in front of 
a little rocky point named Jaburú, and stretches away southward, 
in the general trend of the shore, enclosing behind it a narrow 
and shallow channel which, at the most, is scarcely one-fourth of 
a mile in breadth, and generally less. It is most perfect toward 
the northern end, and has, at irregular intervals, numerous breaks 
or openings which admit the smaller boats that ply along the 
shore. Approaching close to Peña, another rocky point about 
three miles from Jaburú, it ends abruptly; but commencing again 
just to the south, it runs onward to the Ponte da Cruz, terminating 
for good on the rocky shore. The study of the geology of the 
island has shown that the reef follows the submerged, outcropping 
edges of a series of heavy beds of sandstone, which, at times, 
bring up on the shore in the form of rocky points. On this solid 
base the reef appears to have been built, and where, finally, at 
the south, the sandstone leaves the sea and lies upon the beach, 
the coral reef ceases to exist. 
The reef is slightly zigzag in its course, and both edges are 
very jagged, deeply indented and bordered by projecting or out- 
lying masses; but so irregular is every part that it would be quite 
useless for us to try and describe it accurately. At the northern 
end it is generally elevated on the outer side and low and level 
onthe inner. The higher portion varies greatly in width and 
height, and is never flattened on top; it rises rapidly, often 
abruptly, from the water, but descends more gradually on the 
inner side to a level of about one foot above ordinary low tide.. 
a From here there extends inward a very flat surface, which is gen- 
3 ji $ 
aves quite b oo Caste” AI down or even nearly disappear. 
